Strawberry Blonde

I have mostly gray natural color with just a bit of dard brown remaining. Most recently, I have been mixing equal parts of medium brown and reddish brown. What combination of colors will result in a lighter, strawberry blonde? Would prefer to avoid a golden base. Could the neutral blonde and reddish brown in equal parts be the best option? I have a photo of the color, but not sure how to send that to your office for review. Appreciate your advise.